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authorAlexey Bataev <a.bataev@hotmail.com>2019-05-22 19:50:32 +0000
committerAlexey Bataev <a.bataev@hotmail.com>2019-05-22 19:50:32 +0000
commit926938a039dbca89d50348b06cf7cda4924c60f8 (patch)
tree598c3dd691ace052d265ea91935f19505dd54894 /libomptarget/deviceRTLs
parentf8e8d598bf8b2725baf87892119e6952819fce34 (diff)
[OPENMP][NVPTX]Fix barriers and parallel level counters, NFC.
Summary: Parallel level counter should be volatile to prevent some dangerous optimiations by the ptxas. Otherwise, ptxas optimizations lead to undefined behaviour in some cases. Also, use __threadfence() for #pragma omp flush and if the barrier should not be used (we have only one thread in the team), still perform flush operation since the standard requires implicit flush when executing barriers. Reviewers: gtbercea, kkwli0, grokos Subscribers: guansong, jfb, jdoerfert, openmp-commits, caomhin Tags: #openmp Differential Revision: https://reviews.llvm.org/D62199 git-svn-id: https://llvm.org/svn/llvm-project/openmp/trunk@361421 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'libomptarget/deviceRTLs')
-rw-r--r--libomptarget/deviceRTLs/nvptx/src/omp_data.cu3
-rw-r--r--libomptarget/deviceRTLs/nvptx/src/omptarget-nvptx.h2
-rw-r--r--libomptarget/deviceRTLs/nvptx/src/sync.cu4
3 files changed, 6 insertions, 3 deletions
diff --git a/libomptarget/deviceRTLs/nvptx/src/omp_data.cu b/libomptarget/deviceRTLs/nvptx/src/omp_data.cu
index d369da1..0cd9b57 100644
--- a/libomptarget/deviceRTLs/nvptx/src/omp_data.cu
+++ b/libomptarget/deviceRTLs/nvptx/src/omp_data.cu
@@ -31,7 +31,8 @@ __device__ omptarget_nvptx_SimpleMemoryManager
__device__ __shared__ uint32_t usedMemIdx;
__device__ __shared__ uint32_t usedSlotIdx;
-__device__ __shared__ uint8_t parallelLevel[MAX_THREADS_PER_TEAM / WARPSIZE];
+__device__ __shared__ volatile uint8_t
+ parallelLevel[MAX_THREADS_PER_TEAM / WARPSIZE];
__device__ __shared__ uint16_t threadLimit;
__device__ __shared__ uint16_t threadsInTeam;
__device__ __shared__ uint16_t nThreads;
diff --git a/libomptarget/deviceRTLs/nvptx/src/omptarget-nvptx.h b/libomptarget/deviceRTLs/nvptx/src/omptarget-nvptx.h
index cd51538..b85d0a7 100644
--- a/libomptarget/deviceRTLs/nvptx/src/omptarget-nvptx.h
+++ b/libomptarget/deviceRTLs/nvptx/src/omptarget-nvptx.h
@@ -398,7 +398,7 @@ extern __device__ omptarget_nvptx_SimpleMemoryManager
omptarget_nvptx_simpleMemoryManager;
extern __device__ __shared__ uint32_t usedMemIdx;
extern __device__ __shared__ uint32_t usedSlotIdx;
-extern __device__ __shared__ uint8_t
+extern __device__ __shared__ volatile uint8_t
parallelLevel[MAX_THREADS_PER_TEAM / WARPSIZE];
extern __device__ __shared__ uint16_t threadLimit;
extern __device__ __shared__ uint16_t threadsInTeam;
diff --git a/libomptarget/deviceRTLs/nvptx/src/sync.cu b/libomptarget/deviceRTLs/nvptx/src/sync.cu
index d81aa8f..191b046 100644
--- a/libomptarget/deviceRTLs/nvptx/src/sync.cu
+++ b/libomptarget/deviceRTLs/nvptx/src/sync.cu
@@ -62,6 +62,8 @@ EXTERN void __kmpc_barrier(kmp_Ident *loc_ref, int32_t tid) {
// Barrier #1 is for synchronization among active threads.
named_sync(L1_BARRIER, threads);
}
+ } else {
+ __kmpc_flush(loc_ref);
} // numberOfActiveOMPThreads > 1
PRINT0(LD_SYNC, "completed kmpc_barrier\n");
}
@@ -130,7 +132,7 @@ EXTERN void __kmpc_end_single(kmp_Ident *loc, int32_t global_tid) {
EXTERN void __kmpc_flush(kmp_Ident *loc) {
PRINT0(LD_IO, "call kmpc_flush\n");
- __threadfence_system();
+ __threadfence();
}
////////////////////////////////////////////////////////////////////////////////